Some guys have these Olympus waterproof cameras - they are good cameras anyway and being tough and waterproof in a bonus - + they are suprisingly small.
Alun J has one - he could advise.
Maybe this:
http://www.parkcameras.com/Search/waterpro...igital+Cameras/
Or Pentax:
http://www.parkcameras.com/Search/waterpro...igital+Cameras/
Panasonic, canon and Fuji also do versions.
I have a sony normal digital compact camera and have a waterproof case for it (3m\10ft). This is because at the time the tough cameras did not have an AF assist light, but the case was expensive but I got it in Canada which was much better for the wallet!
I find this site a good place to start for reviews:
http://www.trustedreviews.com/digital-cameras/
HTH
Rob